Accessory gearbox for a turbine engine

ABSTRACT

A turbine engine that includes an engine core, an inner cowl, an outer cowl and an accessory gearbox. The engine core includes at least a compressor section, a combustion section, and a turbine section in axial flow arrangement. The accessory gearbox is operably coupled to the engine core and includes a first portion and a second portion.

TECHNICAL FIELD

This disclosure relates to an accessory gearbox, more specifically, anaccessory gearbox for a turbine engine.

BACKGROUND

Gas turbine engines often include an accessory gearbox to power or driveaccessory systems such as fuel pumps, lubrication pumps, aircompressors, scavenge pumps, electrical generators, hydraulic pumps,etc. The accessory gearbox can be driven by one or more components ofthe gas turbine engine. When powered or mechanically driven by the gasturbine engine, the accessory gearbox can interface with the accessorysystems that require different rotational input, torque, or horsepower.

BRIEF DESCRIPTION

Aspects and advantages of the disclosure will be set forth in part inthe following description, or may be obvious from the description, ormay be learned through practice of the disclosure herein.

In one aspect, the disclosure relates to a turbine engine that includesan engine core, an inner cowl radially spaced from the engine core andcircumscribing the engine core, an outer cowl radially spaced from theinner cowl and circumscribing at least a portion of the inner cowl, andan accessory gearbox comprising a first portion located within the innercowl and straddling the engine core and a second portion located betweenthe inner cowl and the outer cowl.

In another aspect, the disclosure relates to a turbine engine thatincludes a fan assembly defining an inlet, an engine core, an inner cowlradially spaced from the engine core and having an inside facecircumscribing at least a portion of the engine core, an outer cowlradially spaced from the inner cowl and circumscribing at least aportion of the inner cowl, a bifurcated airflow path comprising a firstportion extending from the inlet through the engine core and a secondportion extending from the inlet through a secondary airflow pathdefined between the inner cowl and the outer cowl, and an accessorygearbox having a first portion located within the inner cowl and asecond portion, located in the secondary airflow path.

These and other features, aspects and advantages of the presentdisclosure will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateaspects of the disclosure and, together with the description, serve toexplain the principles of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure, including the best mode thereof,directed to one of ordinary skill in the art, is set forth in thespecification, which refers to the appended figures in which:

In the drawings:

FIG. 1 is a schematic view of a turbine engine with a partial sectionalcutaway along a turbine engine axis of rotation illustrating enginestatic structures and an accessory gearbox in the lower half, accordingto aspects of the present disclosure.

FIG. 2 is a rear perspective view of selected components of the turbineengine of FIG. 1 , according to aspects of the present disclosure.

FIG. 3 is a side perspective view of the selected components of theturbine engine of FIG. 1 , further illustrating the accessory gearboxaccording to aspects of the present disclosure.

FIG. 4 illustrates a schematic cross section of the accessory gearbox ofFIG. 2 in the context of selected support structures, according toaspects of the present disclosure.

FIG. 5 illustrates a schematic cross section of an alternative accessorygear box that can be utilized in the turbine engine of FIG. 1 .

FIG. 6 illustrates a schematic cross section of an alternative accessorygear box that can be utilized in the turbine engine of FIG. 1 .

DETAILED DESCRIPTION

One or more aspects described herein provide an accessory gearbox (AGB)provided with an engine core of a turbine engine. The accessory gearboxincludes a first portion and second portion. The first portion of theAGB is located within an inner cowl and straddles the engine core. Thesecond portion, formed with or operably coupled to the first portion,extends at least partially between the inner cowl and the outer cowl. Inthis manner, the core mounted accessory gearbox includes components thatextend beyond the inner cowl into the bifurcated airflow between theinner cowl and the outer cowl, which allows for a more aerodynamicfairing.

Further, the first and second portions of the AGB can provide power tointerfaces defined by at least three different planes. The location ofthe core mounted AGB allows for easier access to the AGB and othercomponents or systems within the turbine engine such as, but not limitedto, fuel lines.

For purposes of illustration, the present disclosure will be describedwith respect to a turbine engine for an aircraft. The disclosure canhave applicability in a variety of vehicles or engines, and can be usedto provide benefits in industrial, commercial, and residentialapplications. Further non-limiting examples of other vehicles or enginesto which the disclosure can relate can include boats, helicopters, cars,or other aquatic, air, space, or land vehicles. Industrial, commercial,or residential applications of the disclosure can include, but are notlimited to, marine power plants, wind turbines, or small power plants.

As used herein, the term “upstream” refers to a direction that isopposite the fluid flow direction, and the term “downstream” refers to adirection that is in the same direction as the fluid flow. The term“fore” or “forward” means in front of something and “aft” or “rearward”means behind something. For example, when used in terms of fluid flow,fore/forward can mean upstream and aft/rearward can mean downstream.

Additionally, as used herein, the terms “radial” or “radially” refer toa direction away from a common center. For example, in the overallcontext of a turbine engine, radial refers to a direction along a rayextending between a center longitudinal axis of the engine and an outerengine circumference. Furthermore, as used herein, the term “set” or a“set” of elements can be any number of elements, including only one.

Additionally, as used herein, elements being “electrically connected,”“electrically coupled,” or “in signal communication” can include anelectric transmission or signal being sent, received, or communicated toor from such connected or coupled elements. Furthermore, such electricalconnections or couplings can include a wired or wireless connection, ora combination thereof.

Also, as used herein, while sensors can be described as “sensing” or“measuring” a respective value, sensing or measuring can includedetermining a value indicative of or related to the respective value,rather than directly sensing or measuring the value itself. The sensedor measured values can further be provided to additional components. Forinstance, the value can be provided to a controller module or processoras defined above, and the controller module or processor can performprocessing on the value to determine a representative value or anelectrical characteristic representative of said value.

All directional references (e.g., radial, axial, proximal, distal,upper, lower, upward, downward, left, right, lateral, front, back, top,bottom, above, below, vertical, horizontal, clockwise, counterclockwise,upstream, downstream, forward, aft, etc.) are used only foridentification purposes to aid the reader's understanding of the presentdisclosure, and should not be construed as limiting on an example,particularly as to the position, orientation, or use of aspects of thedisclosure described herein. Connection references (e.g., attached,coupled, connected, and joined) are to be construed broadly and caninclude intermediate members between a collection of elements andrelative movement between elements unless otherwise indicated. As such,connection references do not necessarily infer that two elements aredirectly connected and in fixed relation to one another. The exemplarydrawings are for purposes of illustration only and the dimensions,positions, order and relative sizes reflected in the drawings attachedhereto can vary.

FIG. 1 is a schematic partial section view of a turbine engine 10 for anaircraft, where an upper section of FIG. 1 illustrates the cross sectionof the turbine engine 10 and a lower section illustrates a schematic ofstatic support structures and an accessory gearbox.

The turbine engine 10 has a centerline or turbine engine axis ofrotation 12 extending forward 14 to aft 16. The turbine engine 10includes, in downstream serial flow relationship, a fan section 18including a fan assembly 20, a compressor section 22 including a boosteror low pressure (LP) compressor 24 and a high pressure (HP) compressor26, a combustion section 28 including a combustor 30, a turbine section32 including a HP turbine 34, and a LP turbine 36, and an exhaustsection 38.

The fan section 18 includes a fan casing 40 surrounding the fan assembly20. The fan assembly 20 includes a plurality of fan blades 42 disposedradially about the turbine engine axis of rotation 12. The HP compressor26, the combustor 30, and the HP turbine 34 form an engine core 44,which generates combustion gases. The engine core 44 is surrounded bycore casing 46, which can be coupled with the fan casing 40.

A HP shaft or HP spool 48 disposed coaxially about the turbine engineaxis of rotation 12 of the turbine engine 10 drivingly connects the HPturbine 34 to the HP compressor 26. A LP shaft or LP spool 50, which isdisposed coaxially about the turbine engine axis of rotation 12 of theturbine engine 10 within the larger diameter annular HP spool 48,drivingly connects the LP turbine 36 to the LP compressor 24 and fanassembly 20. The HP spool 48 and LP spool 50 are rotatable about theengine centerline and couple to a plurality of rotatable elements, whichcan collectively define an inner rotor/stator. While illustrated as arotor, it is contemplated that the inner rotor/stator can be a stator.

The LP compressor 24 and the HP compressor 26 respectively include aplurality of compressor stages 52, 54, in which a set of compressorblades 56, 58 rotate relative to a corresponding set of staticcompressor vanes 60, 62, which can also be called a nozzle, to compressor pressurize the stream of fluid passing through the stage. In a singlecompressor stage 52, 54, multiple compressor blades 56, 58 can beprovided in a ring and can extend radially outwardly relative to theturbine engine axis of rotation 12, from a blade platform to a bladetip, while the corresponding static compressor vanes 60, 62 arepositioned upstream of and adjacent to the rotating compressor blades56, 58. It is noted that the number of blades, vanes, and compressorstages shown in FIG. 1 were selected for illustrative purposes only, andthat other numbers are possible.

The compressor blades 56, 58 for a stage of the compressor can bemounted to a disk 61, which is mounted to the corresponding one of theHP spool 48 and LP spool 50, with each stage having its own disk 61. Thevanes 60, 62 for a stage of the compressor can be mounted to the corecasing 46 in a circumferential arrangement.

The HP turbine 34 and the LP turbine 36 respectively include a pluralityof turbine stages 64, 66, in which a set of turbine blades 68, 70 arerotated relative to a corresponding set of static turbine vanes 72, 74,which can also be called a nozzle, to extract energy from the stream offluid passing through the stage. In a single turbine stage 64, 66,multiple turbine blades 68, 70 can be provided in a ring and can extendradially outwardly relative to the turbine engine axis of rotation 12,from a blade platform to a blade tip, while the corresponding staticturbine vanes 72, 74 are positioned upstream of and adjacent to therotating blades 68, 70. It is noted that the number of blades, vanes,and turbine stages shown in FIG. 1 were selected for illustrativepurposes only, and that other numbers are possible.

The blades 68, 70 for a stage of the turbine can be mounted to a disk71, which is mounted to the corresponding one of the HP spool 48 and LPspool, 50, with each stage having a dedicated disk 71. The vanes 72, 74for a stage of the compressor can be mounted to the core casing 46 in acircumferential arrangement.

Complementary to the rotor portion, the stationary portions of theturbine engine 10, such as the static vanes 60, 62, 72, 74 among thecompressor section 22 and turbine section 32 are also referred toindividually or collectively as an outer rotor/stator. As illustrated,the outer rotor/stator can refer to the combination of non-rotatingelements throughout the turbine engine 10. Alternatively, the outerrotor/stator that circumscribes at least a portion of the innerrotor/stator, can be designed to rotate. The inner or outer rotor/statorcan include at least one component that can be, by way of non-limitingexample, a shroud, vane, nozzle, nozzle body, combustor, hanger, orblade, where the at least one component is a plurality ofcircumferentially arranged component segments having confronting pairsof circumferential ends.

An inner cowl 76 is radially spaced from the engine core 44 and cancircumscribe at least a portion of the engine core 44. The inner cowl 76can include an outside face 78 and an inside face 80, where the insideface 80 of the inner cowl 76 can confront the engine core 44 or the corecasing 46.

A nacelle or outer cowl 82 is radially spaced from the inner cowl 76 andcan circumscribe at least a portion of the inner cowl 76. The outer cowl82 has a radially outer surface 84 and a radial inner surface 86, wherethe radial inner surface 86 confronts the outside face 78 of the innercowl 76. The outer cowl 82 can support or define the fan casing 40.

An accessory gearbox (AGB) 90 can be provided with the engine core 44 orthe core casing 46 and be at least partially confined within the innercowl 76. It is contemplated that the AGB 90 is mounted or operablycoupled to the engine core 44 with a hinge mount. That is, when one ormore clasps or fasteners is removed, the AGB 90 can swing away from atleast part of the engine core 44 or core casing 46 to which a remainderof the AGB 90 remains operably coupled to. The AGB 90 is operablycoupled to the engine core 44 or core casing 46 in a location andorientation so as to provide easy access to the AGB 90 and othercomponent such as, but not limited to, fuel lines, electrical cables,electrical connectors, oil tubes, sight glasses, and fill ports.

An accessory gearbox axis 92 can be defined by the AGB 90. In theillustrated example, the accessory gearbox axis 92 is parallel to theturbine engine axis of rotation 12 when the AGB 90 is fully installedand in use within the turbine engine 10. It is contemplated, however,that the accessory gearbox axis 92 and the turbine engine axis ofrotation 12 can be at any suitable angle and need not be parallel.

The AGB 90 includes a first portion 94 and a second portion 96. Thefirst portion 94 is located within the inner cowl 76. That is, the firstportion 94 is located between the inside face 80 of the inner cowl 76and the engine core 44 or the core casing 46. The first portion 94 ofthe AGB 90 can straddle the engine core 44 or the core casing 46.

The second portion 96 of the AGB 90 is located between the inner cowl 76and the outer cowl 82. That is, the second portion 96 of the AGB 90 islocated between the radial inner surface 86 of the outer cowl 82 and theoutside face 78 of the inner cowl 76. However, it is contemplated that apart of the second portion 96 of the AGB 90 can extend past the radialinner surface 86 of the outer cowl 82. That is, the second portion 96 ofthe AGB 90 can operably couple to one or more components located in theouter cowl 82.

At least one strut 98 can extend radially from the inner cowl 76 to theouter cowl 82. The strut 98 can operably couple the inner cowl 76 andthe outer cowl 82. It is contemplated that at least a part of the secondportion 96 of the AGB 90 is located in the strut 98.

The second portion 96 of the AGB 90 is illustrated as beingperpendicular to the accessory gearbox axis 92. However, this need notbe the case and it is further contemplated that the second portion 96and the accessory gearbox axis 92 can be at any relative angle.

In operation, airflows through the fan section 18 to an inlet 108 thatis defined by the fan assembly 20. Airflow exiting the fan section 18through the inlet 108 enters a bifurcated airflow path. The bifurcatedairflow path includes a first portion or first airflow 100 through theengine core 44 and second portion 96 or second airflow 102 that passesthrough a secondary airflow path 104. Therefore, the inlet 108 can befluidly coupled to the engine core 44 and the secondary airflow path104.

The first airflow 100 is channeled into the LP compressor 24, which thensupplies pressurized airflow 100 to the HP compressor 26, which furtherpressurizes the air. The pressurized airflow 100 from the HP compressor26 is mixed with fuel in the combustor 30 and ignited, therebygenerating combustion gases. Some work is extracted from these gases bythe HP turbine 34, which drives the HP compressor 26. The combustiongases are discharged into the LP turbine 36, which extracts additionalwork to drive the LP compressor 24, and the exhaust gas is ultimatelydischarged from the turbine engine 10 via the exhaust section 38. Thedriving of the LP turbine 36 drives the LP spool 50 to rotate the fanassembly 20 and the LP compressor 24.

A portion of the pressurized airflow 100 can be drawn from thecompressor section 22 as bleed air 106. The bleed air 106 can be drawnfrom the pressurized airflow 100 and provided to engine componentsrequiring cooling. The temperature of pressurized airflow 100 enteringthe combustor 30 is significantly increased. As such, cooling providedby the bleed air 106 is necessary for operating of such enginecomponents in the heightened temperature environments.

The second airflow 102 travels through the secondary airflow path 104defined by the inner cowl 76 and the outer cowl 82. That is, the outsideface 78 of the inner cowl 76 and the radial inner surface 86 of theouter cowl 82 can define the secondary airflow path 104.

The second airflow 102 bypasses the LP compressor 24 and the engine core44 and exits the turbine engine 10. The secondary airflow path 104 caninclude a stationary vane row, and more particularly an outlet guidevane assembly 110, that includes a plurality of airfoil guide vanes 112.More specifically, a circumferential row of radially extending airfoilguide vanes 112 are utilized adjacent the fan section 18 to exert somedirectional control of the second airflow 102.

Some of the air supplied by the fan assembly 20 can bypass the enginecore 44 and be used for cooling of portions, especially hot portions, ofthe turbine engine 10, and/or used to cool or power other aspects of theaircraft. In the context of a turbine engine, the hot portions of theengine are normally downstream of the combustor 30, especially theturbine section 32, with the HP turbine 34 being the hottest portion asit is directly downstream of the combustion section 28. Other sources ofcooling fluid can be, but are not limited to, fluid discharged from theLP compressor 24 or the HP compressor 26.

FIG. 2 further illustrates static support structures of the turbineengine 10 and the location of the second portion 96 of the AGB 90 withrespect thereto. For clarity, FIG. 2 only includes the outer cowl 82,the inner cowl 76, the core casing 46, support struts including thestrut 98, and the second portion 96 of the AGB 90. The strut 98 thatextends through the secondary airflow path 104 includes a first wall 120and a second wall 122 spaced from the first wall 120, although anynumber of walls is contemplated. While illustrated as open, it iscontemplated that the first wall 120 and second wall 122 can be coupledor otherwise connected aft of the second portion 96 of the AGB 90. It isfurther contemplated that the first wall 120 and the second wall 122 canjoin at a point forward of the second portion 96 of the AGB 90. It willbe understood that the strut 98 can form an aerodynamic housing for atleast part of the second portion 96.

An upper strut 124 is illustrated as having a single wall. However, itis contemplated that the upper strut 124 can be reconfigured to house orpartially surround the second portion 96 of the AGB 90. It will beunderstood that the second portion 96 of the AGB 90 can be located inany part of the secondary airflow path 104. This includes but is notlimited to within a strut located anywhere about the turbine engine 10.The second portion 96 can extend from the inner cowl 76 to any suitableradial location including into the outer cowl 82 or radially outwardfrom the secondary airflow path 104.

FIG. 3 further illustrates the AGB 90 provided with the engine core 44.The outer cowl 82, inner cowl 76, and internal portions of the enginecore 44 have not been illustrated for clarity. A set of forksillustrated as a first fork 121 and a second fork 123 can be included inthe AGB 90. As used herein, the term “fork” is a Y-shaped object havingan upright or base from which two arms branch off in differentdirections.

In the illustrated example, the first fork 121 includes a first baseportion 125 defined by a part of the second portion 96 of the AGB 90. Afirst arm 130 and a second arm 132 extend from the first base portion125. The first arm 130 and the second arm 132 are part of the firstportion 94 of the AGB 90 that can straddle the engine core 44 or corecasing 46. That is, the as the base portion 125 extends, forks, splits,branches, or otherwise couples to the first arm 130 and the second arm132, where the first arm 130 and the second arm 132 form a V-shape,U-shape, or the like, in order to cradle, straddle, or otherwisepartially circumscribe the engine core 44 or core casing 46.

Similarly, the second fork 123 can be defined by a second base portion127 that forks, splits, or otherwise couples to a first arm 128 and asecond arm (not shown as it wraps behind the core casing 46) thatstraddle the engine core 44 or core casing 46. It is contemplated thatany number of one or more forks can be included in the AGB 90.

The first fork 121 and the second fork 123 are illustrated as beingspaced along the accessory gearbox axis 92. The first fork 121 and thesecond fork 123 can be coupled via one or more of a drive shaft,gearbox, hydraulic drive, or the like. The drive shaft or a hydraulicdrive can include one or more casings 126 positioned between the firstfork 121 and the second fork 123. It is contemplated that only a singlefork can be included or that additional sections, casing, drive shafts,or the like, can be included to increase the number of interfaces orforks.

The AGB 90 can couple to any number of interfaces, illustrated, by wayof non-limiting example as interfaces 131 a, 131 b, 131 c. Additionally,it is contemplated that the AGB 90 can couple to any number ofcomponents or systems illustrated, by way of non-limiting example assystems 133 a, 133 b, 133 c. Systems powered by the AGB 90 can belocated at axially or radially spaced locations relative to the AGB 90.By way of example, systems or interfaces can include, but are notlimited to, any one or more of an output shaft, fuel pump, transfergearbox, lubrication pump, air compressor, scavenge pump, electricalgenerator, fuel control, fuel pump, permanent magnet alternator,lubrication pump, or hydraulic pump.

FIG. 4 is a cross section further illustrating the AGB 90, the crosssection is a schematic cross section generally taken at the axiallocation of the first fork 121 further illustrated as a cross sectionline in FIG. 2 . The engine core 44 and core casing 46 are schematicallyillustrated along with the turbine engine axis of rotation 12. AC-shaped or arc cross-section can be defined by the first arm 130 andthe second arm 132 and straddle the engine core 44. While no spacing orcoupling components are illustrated between the core casing 46 and theAGB 90 it will be understood that any suitable spacing and componentscan be included. The first arm 130 extends from the accessory gearboxaxis 92 to a first terminating point or first distal surface 134. Thefirst distal surface 134 can have a first end point 136 defined as thepoint on the first distal surface 134 that is radially farthest from theturbine engine axis of rotation 12. A first distance 140 can be measuredradially from the accessory gearbox axis 92 to the first end point 136.

The first arm 130 can include a first plane 144. The two dimensionsdefining the first plane 144 are illustrated by way of example as afirst dimension that is generally perpendicular to the first distalsurface 134 and a second dimension is into/out of the page. As usedherein, the term “generally perpendicular” defines an angle between twoobjects that is between 80 degrees and 100 degrees. Additionally, oralternatively, the plane 144 can be defined by a plane defined by atleast an obtuse angle extending from the yaw or pitch axis (i.e. frominto/out of page, or top to bottom respectively in FIG. 1 ). In FIG. 4example the obtuse is formed with yaw-roll plane. In other examples theplane 144 can be defined by rotation around more than one of these threemutually orthogonal axes. It is further contemplated that the firstplane 144 can form any angle in either dimension with the first distalsurface 134.

A primary set of interfaces 142 a, 142 b can be operably coupled to ordefined by a portion of the first arm 130. The primary set of interfaces142 a, 142 b can extend along or be defined by the first plane 144.While illustrated as two interfaces 142 a, 142 b that lie on the plane144, any number of interfaces in the first plane 144, including one, arecontemplated.

The first arm 130 can define a first arm axis of rotation 146. It iscontemplated that the rotation of an output shaft or other portion ofthe first arm 130 about the first arm axis of rotation 146 can beconsidered an interface of the AGB 90. An interface as defined hereincan be an input to the AGB 90 or an output from the AGB 90. It isfurther contemplated that the first arm 130 can define any number ofaxes of rotations.

The first arm 130 can sweep a first arclength 150 from the accessorygearbox axis 92 to the first distal surface 134. The first arm 130 cancover, straddle, or otherwise wrap around between 5% and 50% of theengine core 44 or the core casing 46. It is contemplated that the lengthof the first arclength 150 is between 1% and 60% the circumference ofthe engine core 44 or the core casing 46.

The second arm 132 extends from the plane of the accessory gearbox axis92 to a second terminating point or second distal surface 154. Thesecond distal surface 154 can have a second end point 156 defined as thepoint on the second distal surface 154 that is radially farthest fromthe turbine engine axis of rotation 12. A second distance 160 can bemeasured radially from the accessory gearbox axis 92 to the second endpoint 156. While illustrated as equal, the first distance 140 can begreater than or less than the second distance 160. That is, the secondportion 96 of the AGB 90 is spaced non-equidistant between the first endpoint 136 and the second end point 156, where the first end point 136and the second end point 156 are defined by the arc cross-section.

The second arm 132 can include a second plane 164. The two dimensionsdefining the second plane 164 are illustrated by way of example as afirst dimension that is generally perpendicular to the second distalsurface 154 and a second dimension is into/out of the page. Similar tothe first plane 144, the second plane 164 can be defined by a planedefined by at least an obtuse angle extending from the yaw or pitch axis(i.e. from into/out of page, or top to bottom respectively in FIG. 1 ).It is further contemplated that the second plane 164 can form any anglein either dimension with the second distal surface 154.

A secondary set of interfaces 162 a, 162 b can be operably coupled to ordefined by a portion of the second arm 132. The secondary set ofinterfaces 162 a, 162 b can be defined by the second plane 164. Whileillustrated as two interfaces 162 a, 162 b that lie on or extend alongthe plane 164, any number of interfaces in the second plane 164,including one, are contemplated.

The second arm 132 can define a second arm axis of rotation 166. It iscontemplated that the rotation of an output shaft or other portion ofthe second arm 132 about the second arm axis of rotation 166 can beconsidered an interface of the AGB 90. It is further contemplated thatthe second arm 132 can define any number of axes of rotations.

The second arm 132 can sweep a second arclength 170 from the accessorygearbox axis 92 to the second distal surface 154. The second arm 132 cancover or otherwise wrap around between 5% and 50% of the engine core 44or the core casing 46. It is contemplated that the length of the secondarclength 170 is between 1% and 60% the circumference of the engine core44 or the core casing 46. While illustrated as equal, the secondarclength 170 can be less than or greater than the first arclength 150.

A third plane 174 can define a tertiary set of interfaces 172 a, 172 bincluded in the second portion 96 of the AGB 90. As illustrated, by wayof non-limiting example, the second portion 96 of the AGB 90 can begenerally perpendicular to the accessory gearbox axis 92. The tertiaryset of interfaces 172 a, 172 b can extend along the third plane 174. Itis contemplated that one or more of the tertiary set of interfaces 172a, 172 b extends past the radial inner surface 86 of the outer cowl 82.That is, the AGB 90 can include the primary set of interfaces 142 a, 142b defined by the first plane 144, the secondary set of interfaces 162 a,162 b defined by the second plane 164, and the tertiary set ofinterfaces 172 a, 172 b defined by the third plane 174. Interfaces caninclude, but are not limited to systems, components, or other engineelements that receive energy from the rotation of the AGB 90 about theaccessory gearbox axis 92. It is contemplated that the interfaces 172 a,172 b, 142 a, 142 b, 162 a and 162 b can correspond to an interface toservice one or more of, or any of an output shaft, fuel pump, transfergearbox, lubrication pump, air compressor, scavenge pump, electricalgenerator, fuel control, fuel pump, permanent magnet alternator,lubrication pump, or hydraulic pump. It is further contemplated that thesecond portion 96 of the AGB 90 can define any number of axes ofrotations.

The third plane 174, similar to the first plane 144 and the second plane164, includes two dimensions illustrated by way of example as a firstdimension that is generally perpendicular to the accessory gearbox axis92, extending radially outward from the longitudinal axis 12, and asecond dimension is into/out of the page. Similar to the first plane 144and the second plane 164, the third plane 174 can be defined by a planedefined by at least an obtuse angle extending from the yaw or pitch axis(i.e. from into/out of page, or top to bottom respectively in FIG. 1 ).It is further contemplated that the second plane 174 can form any anglein either dimension with the accessory gearbox axis 92.

As shown, by way of example, each of the respective pair of interfaces142 a, 142 b, 162 a and 162 b, 172 a, 172 b or axes of rotations 146,166 associated with the respective planes 144, 164, 174 are generallyperpendicular to each other. However, it is contemplated that the anglesbetween the interfaces 142 a, 142 b, 162 a and 162 b, 172 a, 172 b orthe axes of rotations 146, 166 associated with the respective planes144, 164, 174 can be any angle, including between 50 degrees to 100degrees.

A first angle 176 can be defined from the third plane 174 to the firstplane 144 by a clockwise rotation. As illustrated, the first angle 176can be an acute angle, however any angle between, but not including,zero degrees and 180 degrees is contemplated. A second angle 178 can befrom the third plane 174 to the second plane 164 by a counterclockwiserotation. As illustrated, the first angle 178 can be an acute angle,however any angle between, but not including, zero degrees and 180degrees is contemplated. While illustrated as equal, it is contemplatedthat the first angle 176 can be greater than or less than the secondangle 178.

It is contemplated that any number of additional planes defininginterfaces or axes of rotation can extend from or be defined by thefirst portion 94 or the second portion 96. It is also contemplated thatthe additional planes of interfaces or axes of rotation can extend fromor be defined by one or more portions of the first plane 144, secondplane 164, the third plane 174, the first arm axis of rotation 146, thesecond arm axis of rotation 166, the accessory gearbox axis 92, thefirst arclength 150, or the second arclength 170.

In operation, the AGB 90 is operably coupled to one or more componentsof the engine core 44. That is, one or more components of the enginecore 44 provides or otherwise communicates energy to the AGB 90. By wayof non-limiting example, the AGB 90 can be powered by energy provided bya drive shaft located in the engine core 44 along the turbine engineaxis of rotation 12 or the LP spool 50. Additionally, or alternatively,the AGB 90 can be electrically driven using electrical power generatedby the rotation of the engine core 44 or a storage device for electricalenergy.

The AGB 90, when powered, rotates one or more components about theaccessory gearbox axis 92. The rotation about the accessory gearbox axis92 can then provide energy in the form of rotational energy orelectro-magnetic energy to at least one of interfaces from the first setof interfaces 142 a, 142 b, the secondary set of interfaces 162 a, 162b, or the tertiary set of interfaces 172 a, 172 b. The first set ofinterfaces 142 a, 142 b, the secondary set of interfaces 162 a, 162 b,and the tertiary set of interfaces 172 a, 172 b are located in the firstplane 144, the second plane 164, and the third plane 174, respectively.The first plane 144, the second plane 164, and the third plane 174 arethree distinct planes that can be parallel or intersect.

The transfer of energy from the AGB 90 to the first set of interfaces142 a, 142 b, the secondary set of interfaces 162 a, 162 b, and thetertiary set of interfaces 172 a, 172 b can be from the rotation of abevel gear arrangement. That is, one or more of the first set ofinterfaces 142 a, 142 b, the secondary set of interfaces 162 a, 162 b,or the tertiary set of interfaces 172 a, 172 b can be driven using asystem of bevel gears having a shared drive shaft. It is furthercontemplated that the AGB 90 can include multiple motors to providepower to hydraulic or electrically driven interfaces.

The tertiary set of interfaces 172 a, 172 b coupled to or defined by thesecond portion 96 of the AGB 90 allow the first portion 94 of the AGB 90to be smaller. That is, having the second portion 96 of the AGB 90allows the distance between the inner cowl 76 and the engine core 44 orcore casing 46 to decrease. The smaller distance between the inner cowl76 and the engine core 44 or core casing 46 can increase theaerodynamics of the secondary airflow path 104 by decreasing drag on thesecond airflow 102. Additionally, or alternatively, the smaller firstportion 94 of the AGB 90 can provide room for additional components,such as, but not limited to, reverse thruster components.

The AGB 90 as disclosed can be used for smaller applications, such as,but not limited to, regional aircrafts. The AGB 90 having the firstportion 94 between the core casing 46 and the inner cowl 76 and thesecond portion 96 between the inner cowl 76 and the outer cowl 82 allowsfor the engine 10 to include, for example, a slim line nacelle fan cowland/or advanced thrust reversers.

FIG. 5 illustrates an AGB 290, the AGB 290 is similar to the AGB 90previously described. Therefore, like parts will be identified with likenumerals increased by 200, and it is understood that the description oflike parts of the AGB 90 applies to the AGB 290, unless otherwise noted.As with FIG. 4 it will be understood that FIG. 5 schematicallyillustrates the engine core 44 and core casing 46 along with the turbineengine axis of rotation 12 and that while no spacing or couplingcomponents are illustrated between the core casing 46 and the AGB 290 itwill be understood that any suitable spacing and components can beincluded.

A C-shaped or arc cross-section can be defined by a first arm 330 and asecond arm 332. However, unlike the previously described AGB 90, thefirst arm 330 and the second arm 332 of the AGB 290 are not equidistantin length. The first arm 330 extends from an accessory gearbox axis 292to a first terminating point or first distal surface 334. The firstdistal surface 334 can have a first end point 336 defined as the pointon the first distal surface 334 that is radially farthest from theturbine engine axis of rotation 12. A first distance 340 can be measuredradially from the accessory gearbox axis 292 to the first end point 336.

The first arm 330 can include a first plane 344. The two dimensionsdefining the first plane 344 are illustrated by way of example as afirst dimension that is generally perpendicular to the first distalsurface 334 and a second dimension is into/out of the page.Additionally, or alternatively, the plane 344 can be defined by a planedefined by at least an obtuse angle extending from the yaw or pitch axis(i.e. from into/out of page, or top to bottom respectively in FIG. 1 ).In FIG. 5 example the obtuse is formed with yaw-roll plane. In otherexamples the plane 344 can be defined by rotation around more than oneof these three mutually orthogonal axes. It is further contemplated thatthe first plane 344 can form any angle in either dimension with thefirst distal surface 334.

A primary set of interfaces 342 a, 142 b can be operably coupled to ordefined by a portion of the first arm 330. The primary set of interfaces342 a, 342 b can extend along or be defined by the first plane 344.While illustrated as two interfaces 342 a, 342 b that lie on the plane344, any number of interfaces in the first plane 344, including one, arecontemplated.

The first arm 330 can define a first arm axis of rotation 346. It iscontemplated that the rotation of an output shaft or other portion ofthe first arm 330 about the first arm axis of rotation 346 can beconsidered an interface. It is further contemplated that the first arm330 can define any number of axes of rotations.

The first arm 330 can sweep a first arclength 350 from the accessorygearbox axis 292 to the first distal surface 334. The first arm 330 cancover or otherwise wrap around between 5% and 50% of the engine core 44or core casing 46. It is contemplated that the length of the firstarclength 350 is between 1% and 60% the circumference of the engine core44 or core casing 46.

The second arm 332 extends from the plane of the accessory gearbox axis292 to a second terminating point or second distal surface 354. Thesecond distal surface 354 can have a second end point 356 defined as thepoint on the second distal surface 354 that is radially farthest fromthe turbine engine axis of rotation 12. A second distance 360 can bemeasured radially from the accessory gearbox axis 292 to the second endpoint 356. While illustrated as greater than the first distance 340, thesecond distance 360 can be less than or equal to the first distance 340.That is, the second portion 96 of the AGB 290 is spaced non-equidistantbetween the first end point 336 and the second end point 356, where thefirst end point 336 and the second end point 356 are defined by the arccross-section.

The second arm 332 can include a second plane 364. The two dimensionsdefining the second plane 364 are illustrated by way of example as afirst dimension that is generally perpendicular to the second distalsurface 354 and a second dimension is into/out of the page. Similar tothe first plane 344, the second plane 364 can be defined by a planedefined by at least an obtuse angle extending from the yaw or pitch axis(i.e. from into/out of page, or top to bottom respectively in FIG. 1 ).It is further contemplated that the second plane 364 can form any anglein either dimension with the second distal surface 354.

A secondary set of interfaces 362 a, 362 b can be operably coupled to ordefined by a portion of the first arm 332. The secondary set ofinterfaces 362 a, 362 b can be defined by the second plane 164. Whileillustrated as two interfaces 162 a, 162 b that lie on the plane 164,any number of interfaces in the second plane 164, including one, arecontemplated.

The second arm 332 can define a second arm axis of rotation 366. It iscontemplated that the rotation of an output shaft or other portion ofthe second arm 332 about the second arm axis of rotation 366 can beconsidered an interface. It is further contemplated that the second arm332 can define any number of axes of rotations.

The second arm 332 can sweep a second arclength 370 from the accessorygearbox axis 292 to the second distal surface 354. The second arm 332can cover or otherwise wrap around between 5% and 50% of the engine core44 or the core casing 46. It is contemplated that the length of thesecond arclength 370 is between 1% and 60% the circumference of theengine core 44 or the core casing 46. While illustrated as greater, thesecond arclength 370 can be less than or equal to the first arclength350.

A third plane 174 can define a tertiary set of interfaces 372 a, 372 bthat can be included in a second portion 296 of the AGB 290. Asillustrated, by way of non-limiting example, the second portion 296 ofthe AGB 290 can be generally perpendicular to the accessory gearbox axis292. The tertiary set of interfaces 372 a, 372 b can extend along thethird plane 374. It is contemplated that one or more of the tertiary setof interfaces 372 a, 372 b extends past the radial inner surface 86 ofthe outer cowl 82. That is, the AGB 90 can include the primary set ofinterfaces 342 a, 342 b defined by the first plane 344, the secondaryset of interfaces 362 a, 362 b defined by the second plane 364, and thetertiary set of interfaces 372 a, 372 b defined by the third plane 374.Interfaces can include, but are not limited to systems, components, orother engine elements that receive energy from the rotation of the AGB290 about the accessory gearbox axis 292. It is contemplated that theinterfaces can include, but are not limited to any one or more of anoutput shaft, fuel pump, transfer gearbox, lubrication pump, aircompressor, scavenge pump, electrical generator, fuel control, fuelpump, permanent magnet alternator, lubrication pump, or hydraulic pump.It is further contemplated that the second portion 296 of the AGB 290can define any number of axes of rotations.

The third plane 374, similar to the first plane 344 and the second plane364, includes two dimensions illustrated by way of example as a firstdimension that is generally perpendicular to the accessory gearbox axis292, extending radially outward from the longitudinal axis 12, and asecond dimension is into/out of the page. Similar to the first plane 344and the second plane 364, the third plane 374 can be defined by a planedefined by at least an obtuse angle extending from the yaw or pitch axis(i.e. from into/out of page, or top to bottom respectively in FIG. 1 ).It is further contemplated that the second plane 374 can form any anglein either dimension with the accessory gearbox axis 292.

As shown, by way of example, each of the respective pair of interfaces342 a, 342 b, 362 a and 362 b, 372 a, 372 b or axes of rotations 346,366 associated with the respective planes 344, 364, 374 are generallyperpendicular to each other. However, it is contemplated that the anglesbetween the interfaces 342 a, 342 b, 362 a and 362 b, 372 a, 372 b orthe axes of rotations 346, 366 associated with the respective planes344, 364, 374 can be any angle, including between 50 degrees to 100degrees.

It is contemplated that any number of additional planes defininginterfaces or axes of rotation can extend from or be defined by a firstportion 294 or the second portion 296. It is also contemplated that theadditional planes defining interfaces or axes of rotation can extendfrom or be defined by one or more portions of the first plane 344,second plane 364, the third plane 374, the first arm axis of rotation346, the second arm axis of rotation 366, the accessory gearbox axis292, the first arclength 350, or the second arclength 370.

FIG. 6 illustrates an AGB 490 that is similar to the AGB 90 and the AGB290 previously described. Therefore, like parts will be identified withlike numerals further increased by 200, and it is understood that thedescription of like parts of the AGB 90 and AGB 290 applies to the AGB490, unless otherwise noted. As with FIG. 4 it will be understood thatFIG. 6 schematically illustrates the engine core 44 and core casing 46along with the turbine engine axis of rotation 12 and that while nospacing or coupling components are illustrated between the core casing46 and the AGB 490 it will be understood that any suitable spacing andcomponents can be included.

One difference is that the AGB 490 includes a V-shaped cross-sectiondefined by a first arm 530 and a second arm 532. The first arm 530extends from an accessory gearbox axis 492 to a first terminating pointor first distal surface 534. The first distal surface 534 can have afirst end point 536 defined as the point on the first distal surface 534that is radially farthest from the turbine engine axis of rotation 12. Afirst distance 540 can be measured radially from the accessory gearboxaxis 492 to the first end point 536.

The first arm 530 can include a first plane 544. The two dimensionsdefining the first plane 544 are illustrated by way of example as afirst dimension that is generally perpendicular to the first distalsurface 534 and a second dimension is into/out of the page. It isfurther contemplated that the first plane 544 can form any angle ineither dimension with the first distal surface 534.

A primary set of interfaces 542 a, 542 b can be operably coupled to ordefined by a portion of the first arm 530. The primary set of interfaces542 a, 542 b can extend along or be defined by the first plane 544.While illustrated as two interfaces 542 a, 542 b that lie on the plane544, any number of interfaces in the first plane 544, including one, arecontemplated.

The first arm 530 can define a first arm axis of rotation 546. It iscontemplated that the rotation of an output shaft or other portion ofthe first arm 530 about the first arm axis of rotation 546 can beconsidered an interface. It is further contemplated that the first arm530 can define any number of axes of rotations.

The first arm 530 can sweep a first arm length 551 from the accessorygearbox axis 492 to the first distal surface 534. The first arm 530 cancover between 5% and 50% of the engine core 44 or the core casing 46. Itis contemplated that the first arm length 551 is between 1% and 60% thecircumference of the engine core 44 or the core casing 46.

The second arm 532 extends from the plane of the accessory gearbox axis492 to a second terminating point or second distal surface 554. Thesecond distal surface 554 can have a second end point 556 defined as thepoint on the second distal surface 554 that is radially farthest fromthe turbine engine axis of rotation 12. A second distance 560 can bemeasured radially from the accessory gearbox axis 492 to the second endpoint 556. While illustrated as greater than the first distance 540, thesecond distance 560 can be less than or equal to the first distance 540.That is, the second portion 496 of the AGB 490 is spaced non-equidistantbetween the first end point 536 and the second end point 556, where thefirst end point 536 and the second end point 556 are defined by the arccross-section.

The second arm 532 can include a second plane 564. The two dimensionsdefining the second plane 564 are illustrated by way of example as afirst dimension that is generally perpendicular to the second distalsurface 554 and a second dimension is into/out of the page. It isfurther contemplated that the second plane 564 can form any angle ineither dimension with the second distal surface 554.

A secondary set of interfaces 562 a, 562 b can be operably coupled to ordefined by a portion of the first arm 532. The secondary set ofinterfaces 562 a, 562 b can be defined by the second plane 564. Whileillustrated as two interfaces 562 a, 562 b that lie on or extend alongthe plane 564, any number of interfaces in the second plane 564,including one, are contemplated.

The second arm 532 can define a second arm axis of rotation 566. It iscontemplated that the rotation of an output shaft or other portion ofthe second arm 532 about the second arm axis of rotation 566 can beconsidered an interface. It is further contemplated that the second arm532 can define any number of axes of rotations.

The second arm 532 can have a second arm length 571 from the accessorygearbox axis 492 to the second distal surface 554. The second arm 532can cover between 5% and 50% of the engine core 44 or the core casing46. It is contemplated that the second arm length 571 is between 1% and60% the circumference of the engine core 44 or the core casing 46. Whileillustrated as equal, the second arm length 571 can be greater than orless than the first arm length 551.

A third plane 574 can define a tertiary set of interfaces 572 a, 572 bcan be included in a second portion 496 of the AGB 490. As illustrated,by way of non-limiting example, the second portion 496 of the AGB 490can be perpendicular to the accessory gearbox axis 492. The tertiary setof interfaces 572 a, 572 b can extend along a third plane 574. It iscontemplated that one or more of the tertiary set of interfaces 572 a,572 b extends past the radial inner surface 86 of the outer cowl 82.That is, the AGB 490 can include the primary set of interfaces 542 a,542 b defined by the first plane 544, the secondary set of interfaces562 a, 562 b defined by the second plane 564, and the tertiary set ofinterfaces 572 a, 572 b defined by the third plane 574. Interfaces caninclude, but are not limited to systems, components, or other engineelements that receive energy from the rotation of the AGB 490 about theaccessory gearbox axis 492. It is contemplated that the interfaces caninclude, but are not limited to any one or more of an output shaft, fuelpump, transfer gearbox, lubrication pump, air compressor, scavenge pump,electrical generator, fuel control, fuel pump, permanent magnetalternator, lubrication pump, or hydraulic pump. It is furthercontemplated that the second portion 496 of the AGB 490 can define anynumber of axes of rotations.

The third plane 574, similar to the first plane 544 and the second plane564, includes two dimensions illustrated by way of example as a firstdimension that is generally perpendicular to the accessory gearbox axis492, extending radially outward from the longitudinal axis 12, and asecond dimension is into/out of the page. Similar to the first plane 544and the second plane 564, the third plane 574 can be defined by a planedefined by at least an obtuse angle extending from the yaw or pitch axis(i.e. from into/out of page, or top to bottom respectively in FIG. 1 ).It is further contemplated that the second plane 574 can form any anglein either dimension with the accessory gearbox axis 492.

As shown, by way of example, each of the respective pair of interfaces542 a, 542 b, 562 a and 562 b, 572 a, 572 b or axes of rotations 546,566 associated with the respective planes 544, 564, 574 are generallyperpendicular to each other. However, it is contemplated that the anglesbetween the interfaces 542 a, 542 b, 562 a and 562 b, 572 a, 572 b orthe axes of rotations 546, 566 associated with the respective planes544, 564, 574 can be any angle, including between 50 degrees to 100degrees.

It is contemplated that any number of additional planes defininginterfaces or axes of rotation can extend from or be defined by a firstportion 494 or the second portion 496. It is also contemplated that theadditional planes defining interfaces or axes of rotation can extendfrom or be defined by one or more portions of the first plane 544,second plane 564, the third plane 574, the first arm axis of rotation546, the second arm axis of rotation 566, the accessory gearbox axis492, the first arm length 551, or the second arm length 571.

Benefits of aspects of the disclosure include improved fuel efficiency.The core mounted accessory gearbox with components that tangentiallyextend beyond the inner cowl into the bifurcated airflow allows for amore aerodynamic fairing. That is, because a portion of the AGB isbetween the inner cowl and outer cowl the inner or outer cowls can besmaller and/or more streamlined or aerodynamic. The improved airflowthrough the cowls improves fuel efficiency.

The accessory gearbox, as described herein, can include a smaller innercowl or outer cowl. The smaller inner cowl and/or outer cowl can alsoprovide a cost and weight savings.

The core mounted accessory gearbox, as disclosed herein, improvesmaintainability and accessibility, as the accessory gearbox is locatedadjacent a point of entry to the turbine engine.

The core mounted accessory gear box, as disclosed herein, can be usedfor smaller applications, such as, but not limited to, regionalaircrafts. The accessory gear box having the first portion between thecore casing and the inner cowl and the second portion between the innercowl and the outer cowl allows the accessory gear box to have a smallerfirst portion. The accessory gear box with the smaller first portionallows for the turbine engine 10 to have additional components, such as,but not limited to, reverse thruster components and/or a slim linenacelle fan cowl.

Further aspects of the disclosure are provided by the subject matter ofthe following clauses:

1. A turbine engine, comprising an engine core, an inner cowl radiallyspaced from the engine core and circumscribing the engine core, an outercowl radially spaced from the inner cowl and circumscribing at least aportion of the inner cowl, and an accessory gearbox comprising a firstportion located within the inner cowl and straddling the engine core anda second portion located between the inner cowl and the outer cowl.

2. The turbine engine of any preceding clause wherein the accessorygearbox defines an accessory gearbox axis that is parallel to a turbineengine axis of rotation.

3. The turbine engine of any preceding clause wherein the second portionof the accessory gearbox is perpendicular to the accessory gearbox axis.

4. The turbine engine of any preceding clause wherein the accessorygearbox includes a primary set of interfaces defined by a first plane, asecondary set of interfaces defined by a second plane, and a tertiaryset of interfaces defined by a third plane.

5. The turbine engine of any preceding clause wherein the first portionof the accessory gearbox comprises a V-shaped cross-section.

6. The turbine engine of any preceding clause wherein the V-shapedcross-section defines a first surface perpendicular the first plane anda second surface perpendicular to the second plane.

7. The turbine engine of any preceding clause wherein the first portionof the accessory gearbox comprises a C-shaped or arc cross-section.

8. The turbine engine of any preceding clause wherein the arccross-section defines a first end point and a second end point and thesecond portion of the accessory gearbox is spaced non-equidistantbetween the first end point and the second end point.

9. The turbine engine of any preceding clause wherein at least a part ofthe second portion of the accessory gearbox extends past an innersurface of the outer cowl.

10. The turbine engine of any preceding clause, further comprising astrut that extends radially from the inner cowl and operably couples theinner cowl and the outer cowl.

11. The turbine engine of any preceding clause wherein at least a partof the second portion of the accessory gearbox is located in the strut.

12. The turbine engine of any preceding clause wherein the engine corecomprises at least a compressor section, a combustion section, and aturbine section in axial flow arrangement.

13. A turbine engine comprising a fan assembly defining an inlet, anengine core, an inner cowl radially spaced from the engine core andhaving an inside face circumscribing at least a portion of the enginecore, an outer cowl radially spaced from the inner cowl andcircumscribing at least a portion of the inner cowl, a bifurcatedairflow path comprising a first portion extending from the inlet throughthe engine core and a second portion extending from the inlet through asecondary airflow path defined between the inner cowl and the outercowl, and an accessory gearbox having a first portion located within theinner cowl and a second portion, located in the secondary airflow path.

14. The turbine engine of any preceding clause, further comprising astrut that extends radially through the secondary airflow path andcoupling the inner cowl and the outer cowl, wherein the second portionof the accessory gearbox is located in the strut.

15. The turbine engine of any preceding clause wherein the accessorygearbox defines an accessory gearbox axis that is parallel to a turbineengine axis of rotation.

16. The turbine engine of any preceding clause wherein the accessorygearbox includes a primary set of interfaces defined by a first plane, asecondary set of interfaces defined by a second plane, and a tertiaryset of interfaces defined by a third plane.

17. The turbine engine of any preceding clause wherein the secondportion of the accessory gearbox is perpendicular to the accessorygearbox axis.

18. The turbine engine of any preceding clause wherein the first portionof the accessory gearbox comprises a C-shaped or arc cross-section.

19. The turbine engine of any preceding clause wherein the arccross-section defines a first end point and a second end point and thesecond portion of the accessory gearbox is spaced non-equidistantbetween the first end point and the second end point.

20. The turbine engine of any preceding clause wherein at least a partof the second portion of the accessory gearbox extends past an innersurface of the outer cowl.

What is claimed is:
 1. A turbine engine, comprising: a fan assemblydefining an inlet; an engine core; an inner cowl radially spaced fromthe engine core and circumscribing the engine core; an outer cowlradially spaced from the inner cowl and circumscribing at least aportion of the inner cowl, the outer cowl including a radially innersurface; a bifurcated airflow path comprising a first portion extendingfrom the inlet through the engine core and a second portion extendingfrom the inlet through a secondary airflow path defined between theinner cowl and the outer cowl; and an accessory gearbox comprising: afirst portion located within the inner cowl and straddling the enginecore, wherein the first portion includes a first arm and a second arm;and a second portion located between the inner cowl and the outer cowl,wherein the second portion extends from the first arm and the second armof the first portion to define at least one fork; wherein a primary setof interfaces is defined by a portion of the first arm, wherein asecondary set of interfaces is defined by a portion of the second arm,wherein a tertiary set of interfaces is defined by the second portion ofthe accessory gearbox, wherein the tertiary set of interfaces includesat least a first interface and a second interface, wherein the firstinterface is located within the secondary air flow path, and wherein thesecond interface is located radially outward of the radially innersurface of the outer cowl.
 2. The turbine engine of claim 1 wherein theaccessory gearbox defines an accessory gearbox axis that is parallel toa turbine engine axis of rotation.
 3. The turbine engine of claim 2wherein the second portion of the accessory gearbox is perpendicular tothe accessory gearbox axis.
 4. The turbine engine of claim 2 wherein theaccessory gearbox includes the primary set of interfaces defined by afirst plane, the secondary set of interfaces defined by a second plane,and the tertiary set of interfaces defined by a third plane.
 5. Theturbine engine of claim 4 wherein the first portion of the accessorygearbox comprises a V-shaped cross-section.
 6. The turbine engine ofclaim 1 wherein the first portion of the accessory gearbox comprises aC-shaped or arc cross-section.
 7. The turbine engine of claim 6 whereinthe arc cross-section defines a first end point and a second end pointand the second portion of the accessory gearbox is spacednon-equidistant between the first end point and the second end point. 8.The turbine engine of claim 1 wherein at least a part of the secondportion of the accessory gearbox extends past the radially inner surfaceof the outer cowl.
 9. The turbine engine of claim 1, further comprisinga strut that extends radially from the inner cowl and operably couplesthe inner cowl and the outer cowl.
 10. The turbine engine of claim 9wherein at least a part of the second portion of the accessory gearboxis located in the strut.
 11. A turbine engine comprising: a fan assemblydefining an inlet; an engine core; an inner cowl radially spaced fromthe engine core and having an inside face circumscribing at least aportion of the engine core; an outer cowl radially spaced from the innercowl and circumscribing at least a portion of the inner cowl, the outercowl including a radially inner surface; a bifurcated airflow pathcomprising a first portion extending from the inlet through the enginecore and a second portion extending from the inlet through a secondaryairflow path defined between the inner cowl and the outer cowl; and anaccessory gearbox comprising: a first portion located within the innercowl, the first portion comprising: a first arm; a second arm; a primaryset of interfaces defined by a portion of the first arm, and a secondaryset of interfaces defined by a portion of the second arm; and a secondportion extending from the first portion and at least partially locatedin the secondary airflow path, wherein the second portion includes atertiary set of interfaces, wherein the tertiary set of interfacesincludes a first interface located within the secondary airflow path anda second interface located in the outer cowl.
 12. The turbine engine ofclaim 11, further comprising a strut that extends radially through thesecondary airflow path and coupling the inner cowl and the outer cowl,wherein the second portion of the accessory gearbox is located in thestrut.
 13. The turbine engine of claim 11 wherein the accessory gearboxdefines an accessory gearbox axis that is parallel to a turbine engineaxis of rotation.
 14. The turbine engine of claim 13 wherein the secondportion of the accessory gearbox is perpendicular to the accessorygearbox axis.
 15. The turbine engine of claim 13 wherein the firstportion of the accessory gearbox comprises a C-shaped or arccross-section.
 16. The turbine engine of claim 15 wherein the arccross-section defines a first end point and a second end point and thesecond portion of the accessory gearbox is spaced non-equidistantbetween the first end point and the second end point.
 17. The turbineengine of claim 11 wherein the tertiary set of interfaces operablycouple to one or more components located in the outer cowl.